One thing you have to realize though is that both of those skills are different kinds really. Achilles is more of a boss skill and Beholder Healing is more of a training skill. I'm a 189 Dark Knight that was able to survive 2 tail hits at HT because of Achilles being maxed out and lowering the damage to only 24.5k and 25.4k. Beholder heal though is a great skill especially at skels cause all you really need to do is rush and crush if your a Pure spear. Sorry Pure P/a's, I can't really speak from your point of view. All in all if your more of a bosser only type, go for Achilles and if you train more than boss, stick with the healer. 